The bakery was called Alden Merrill and they were famous and they are closed now. Whole foods is in Wayland and I'm really not that thrilled with their bakery as everything is organic and lacks taste for it. No, organic doesn't mean it has to lack taste but most things are disappointing there.
On the other hand Sudbury Farms Grocery store which is now part of the Roche Brothers Chain but a little different has a very good bakery. I would also recommend posting your question to the Boston Area Board as most people in Sudbury and surrounding area would be there not in this board. I just came here on a whim.
Another options is a new place called Café Decadence on Rt. 20 in Sudbury you might want to give them a call I don’t know if they do cakes but I’d be they would if you called. We got our daughter’s birthday cake at Sudbury Farms now that Alden Merrill is closed and were very pleased though.